This report describes the typical weather at the Tromsø Airport (Tromsø, Norway) weather station over the course of an average October. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Tromsø has a humid subarctic continental climate with cool summers and no dry season. The area within 25 mi of this station is covered by tundra (47%), oceans and seas (36%), and forests (14%).
The month of October is characterized by falling daily high temperatures, with daily highs decreasing from 46Â°F to 38Â°F over the course of the month, exceeding 51Â°F or dropping below 30Â°F only one day in ten.
Over the course of October, the length of the day is very rapidly decreasing. From the start to the end of the month, the length of the day decreases by 4:26 hours, implying an average day-over-day decrease of 8.6 minutes.
The shortest day of the month is October 31 with 6:39 hours of daylight; the longest day is October 1 with 11:05 hours of daylight.
The earliest sunrise is at 7:01am on October 1; the latest sunset is at 6:06pm on October 1; the latest sunrise is at 8:49am on October 27; the earliest sunset is at 2:47pm on October 31.
Daylight savings time (DST) ends at 2:00am on October 28, 2012, shifting sunrise and sunset to an hour earlier.
The median cloud cover is 88% (mostly cloudy) and does not vary substantially over the course of the month.
On October 16, a representative day, the sky is clear or mostly clear 18% of the time, partly cloudy 19% of the time, and mostly cloudy or overcast 56% of the time.
The average probability that some form of precipitation will be observed in a given day is 75%, with little variation over the course of the month.
Throughout October, the most common forms of precipitation are moderate rain, moderate snow, light rain, and light snow.
Moderate rain is the most severe precipitation observed during 45% of those days with precipitation. It is most likely around October 1, when it is observed during 43% of all days.
Moderate snow is the most severe precipitation observed during 27% of those days with precipitation. It is most likely around October 31, when it is observed during 29% of all days.
Light rain is the most severe precipitation observed during 13% of those days with precipitation. It is most likely around October 1, when it is observed during 12% of all days.
Light snow is the most severe precipitation observed during 10% of those days with precipitation. It is most likely around October 31, when it is observed during 10% of all days.
The likelihood of snow falling is highest around October 31, occurring in 40% of days.
Accumulation at this location in October is extremely unlikely. The chances of there being snow on the ground are highest around October 13, occurring 3% of the time.
The snow is typically at its deepest on October 31, with a median depth of 4.5"; the depth exceeds 4.5" only one year out of ten.
The relative humidity typically ranges from 65% (mildly humid) to 93% (very humid) over the course of a typical October, rarely dropping below 50% (comfortable) and reaching as high as 100% (very humid).
The air is driest around October 2, at which time the relative humidity drops below 73% (humid) three days out of four; it is most humid around October 1, rising above 90% (very humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a typical October, the dew point typically varies from 24Â°F (dry) to 39Â°F (dry) and is rarely below 15Â°F (dry) or above 46Â°F (dry).
Over the course of October typical wind speeds vary from 0 mph to 18 mph (calm to fresh breeze), rarely exceeding 28 mph (strong breeze).
The highest average wind speed of 10 mph (gentle breeze) occurs around October 30, at which time the average daily maximum wind speed is 18 mph (fresh breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around October 1, at which time the average daily maximum wind speed is 15 mph (moderate breeze).